Current capacity of bundle conductors. 2

[PeZeKa]

Hi all,
Please advise me where I can found standard or document /recommendation/ gives method to calculate permissible current for bundle conductor used in over had transition lines 220 kV
Thanks !

 

[7anoter4]

Since the clearance between conductors in a bundle it has to be more than 5-7 times the conductor diameter- in order to reduce corona losses- then each cable may be considered alone [no influenced by other presence].
This match also the NEC art. 392.80 or IEC 60287-2-1 Table 2 where if the clearance between
single-core cables in free air it is more than 0.75-1 times the cable overall diameter then each cable could be considered alone.
DETERMINATION OF BARE OVERHEAD CONDUCTOR RATING /2000[PJM Transmission System] states:
Rating of bundled conductors may be approximated by multiplying the value shown in the appropriate table by the number of subconductors in the bundle.
So you may calculate the ampacity following IEEE-738 for instance.